Dental anchoring pin and head therefor

ABSTRACT

A dental anchor for securing a superstructure to a tooth understructure comprising an elongate member which integrally includes a self-threading anchoring portion for operative association with the tooth understructure. The elongate member further includes an enlarged headed anchoring portion for operative association with the superstructure to be mounted upon the understructure. The enlarged head acts to resist or enhance resistance to displacement of the superstructure relative to the understructure axially along the dental anchor. The elongate member is further integrally provided with a manipulating portion for permitting manipulation of the self-threading anchoring portion thereof. The manipulating portion is spaced from the enlarged headed anchoring portion by a weakened portion of reduced thickness the latter for permitting self-severing of the manipulating portion from the enlarged headed anchoring portion selectively.

United States Patent Weissman 51 July 11,1972

[54] DENTAL ANCHORING PIN AND HEAD THEREFOR [72] Inventor: BernardWebsrnan, 304 Ashland Place,

Brooklyn, NY. l12l7 [22] Filed: Jan. 20, i971 [2i] AppLNo: "18,045

Primary Emminer-Robert Peshock Attorney-Friedman & Goodman ABSTRACT Adental anchor for securing a superstructure to a tooth understructurecomprising an elongate member which integrally includes a self-threadinganchoring portion for operative as sociation with the toothunderstructure. The elongate member further includes an enlarged headedanchoring portion for operative asociation with the superstructure to bemounted upon the understructure. The enlarged head acts to resist orenhance resistance to displacement of the superstructure relative to theunderstructure axially along the dental anchor. The elongate member isfurther integrally provided with a manipulating portion for pennittingmanipulation of the self-threading anchoring portion thereof. Themanipulating portion is spaced from the enlarged headed anchoringportion by a weakened portion of reduced thickness the latter forpermitting self-severing of the manipulating portion from the enlargedheaded anchoring portion selectively.

DENTAL ANCHORING PIN AND I-IEAD THEREFOR BACKGROUND OF THE DISCLOSUREThe present invention relates to dentistry in general and moreparticularly to an improvement in apparatus for building superstructureson broken or undermined dentition.

In the dental operation of anchoring a superstructure to theunderstructure, there are usually drilled a number of channels into thetooth or understructure. Anchoring pins are then inserted into thechannels in protruding relation and the ex posed portion of the pins areused for anchoring the superstructure. These pins are extremely small,i.e., on the order of 0.03 inches in diameter and 0.2 inches in length.Inasmuch as these pins are extremely small, there only extends from theunderstructure, a portion of the pin which is of minimal extent. As aresult, therefore, in order to more effectively anchor thesuperstructure to the understructure, a plurality of these pins must befirst embedded in the understructure at various angles relative to oneanother. The result of the inclined relationship of these anchoring pinsrelative to one another is to effect an anchoring tendency that one ofthe pins, if positioned alone in the understructure, would not itselffully accomplish.

More often than not, however, notwithstanding the fact that a luralityof these pins are deposited into the understructure in a manner asdiscussed above, the anchoring effect diminishes after a period of timeand the superstructure eventually loosens from the understructure whichis clearly undesirable.

SUMMARY OF THE INVENTION Accordingly, it is an object of the presentinvention to provide a highly novel and effective means for building asuperstructure on broken or underminded dentition.

Another object is to provide means whereby the potential supportcapacity of the understructure of the tooth is made available foranchoring the superstructure thereto.

A further object of the invention is to provide a highly novel,efficient and long lasting anchoring means, whereby the superstructureis anchored to broken or underminded dentition.

A still further object of the present invention is to provide a moreadequately enhanced resistance against displacement of thesuperstructure relative to the understructure axially along theanchoring means of the present invention.

Another object of the present invention is to provide an anchoring meanswith self-severing structure to permit selec tive severing of theanchoring means at a desirable position.

These objects are achieved by providing a dental anchor for securing asuperstructure to a tooth understructure comprising an elongate memberwhich integrally includes a selfthreading anchoring portion foroperative association with the tooth understructure. The elongate memberfurther includes an enlarged headed anchoring portion for operativeassociation with the superstructure to be mounted upon theunderstructure. The enlarged head acts to resist or enhance resistanceto displacement of the superstructure relative to the understructureaxially along the dental anchor. The elongate member is furtherintegrally provided with a manipulating portion for permittingmanipulation of the self-threading anchoring portion thereof. Themanipulating portion is spaced from the enlarged headed anchoringportion by a weakened portion of reduced thickness, the latter forpermitting selfsevering of the manipulating portion from the enlargedheaded anchoring portion selectively.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and many of theattendant advantages of the present invention will be readilyappreciated and better understood by reference to the following detaileddescription when considered in connection with the accompanying drawingin which like reference numerals designate like parts throughout thefigures thereof and wherein:

FIG. I is a cross-sectional view of a tooth or dentition with itssurface excavated prior to building a superstructure thereon;

FIG. 2 is a cross-sectional view of a tooth similar to FIG. 1, andillustrates the step of providing channels in the dentition pursuant tothe invention;

FIGS. 3 and 4 are enlarged front and side views respectively of theanchoring pin illustrating the fracture portion and head thereofpursuant to the invention;

FIG. 5 is a view similar to FIG. 2 and illustrates the stage ofinserting the anchoring pins into the tooth understructure pursuant tothe invention;

FIG. 6 is a view similar to FIG. 5 and illustrates the anchoring pinsprojecting from the tooth understructure; and

FIG. 7 is a view similar to FIG. 6 and illustrates the anchoring pins assecuring the superstructure to the tooth understructure.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawing,wherein like reference characters designate like or corresponding partsthroughout the several views, there is shown in FIG. 1 a tooth ordentition 10in the soft tissue or gingiva I2 of the human gum. As iswell known to those skilled in the art, the body 14 of the tooth 10 isformed of dentin and encloses a pulp channel 16. The dentin projectingfrom the gingiva is covered by a layer 18 of enamel. In order to preparethe dentition for building a superstructure thereon, a portion 20 of theenamel and a portion 22 of the dentin are excavated, thereby to removedecayed and un derminded understructure and form the excavated surface24 free of decay.

The first step in providing a superstructure 26 (FIG. 7) pursuant to thepresent invention, is to provide a plurality of channels 28, as shown inFIG. 2, extending into the dentin l4 from the excavated surface 24. Forthis purpose, a spiral drill 30 is urged into the dentin in aconventional manner. As presently constructed, the bit 34 of drill 30may have a preferred diameter of, for example, 0.028 inches. The numberof channels 28 needed in a particular understructure will vary with thearea of excavated surface 24 and portion of dentin 20 and enamel 22 thatmust be replaced by superstructure. Indeed, a single channel may besufficient in some instances. However, more likely than not, a pluralityof channels 28 are often necessary, and this requirement underscorescertain of the principles of the present invention, as will be discussedbelow.

The second step in providing a superstructure 26 pursuant to the presentinvention is to insert the anchoring pins 36 into each of the channels28. In the preferred embodiment, as seen in FIGS. 3 and 4, the anchoringpins 36 are constituted of stainless steel, have respectiveself-threading body portions 38 provided with a bevel end 40 and amanipulating portion 42. Between the manipulation portion 42 and thebody portion 38, a fracture or weakened portion 39 is provided tofacilitate severing the manipulating portion 42 from the body portion38. The manipulating portion 42 is provided with torque transferringmeans or laterally opposing faces 46 which terminate in the marginaledge 48. The manipulating portion 42 further includes a frusto-conicalguide portion 49 terminating in a point of minimal diameter the latterto constitute the fracture or weakened portion 39. As presentlyconstructed in the preferred embodiment, the body portion 38 has adiameter of, for example, 0.030 inches. Consequently, it is apparentthat X, shown in FIG. 6 as representing the diameter of the body portion38, is greater than the dimension X shown in FIG. 2 as representing thediameter of the channel 28. Thus, the body portion 38 may be tightlythreaded into its respective channel 28.

As illustrated clearly in FIGS. 3 and 4, the anchoring pins 36 are eachprovided with an anchoring flange head 50 or, as will be evident fromthe description below, a displacement resist ing means that preventsdisplacement of the superstructure 26 relative to the toothunderstructure l4 axially along the pins 36. Theianchoring flange head50 includes opposing annular faces Sl and 52 of greater lateraldimension than that of the body portion 38 for enhancing the resistanceagainst displacement of the superstructure 26 relative to theunderstructure 14.

A tool attachment 60 is provided to insert the anchoring pins 36 intochannels 28. As is best shown in FIG. 5, the tool 60 is comprised of abody 62 having knurled end 64. At its other end, the body 62 has a pairof laterally spaced limbs or gripping prongs 68 adapted to receive themanipulating portion 42 of the anchoring pin 36. As is illustrated inFIG. 5, the opening formed between the prongs 68 includes an axiallyextending bore 69 which is diametrically extended to form diametricallyopposite restrictive channels into which the lateral faces 46 of themanipulating portion 42 may be seated.

The third step, pursuant to the invention, is to insert an anchoring pin36 into a channel 28. The manipulating portion 42 of a pin 36 isinserted and fully seated between the prongs 68. The tool 60 is thenused to guide the bevel end 40 of the pin 36 into a channel opening 28.A slight downward pressure, in combination with a clockwise rotation isused to thread the pin 36 to the bottom of the channel 28. Sincediameter X of the pin 36 exceeds diameter X of the channel 28, thethreaded portion 38 will thread itself into the dentin side walls ofchannel 28. When fully inserted into a channel 28, the manipulatingportion 42, the anchoring flange head 50, and a small exposed portion ofthe threaded body portion 38, will project above the excavated surface24.

Upon further rotation of the tool 60, with the pin 36 fully seated inits associated channel 28, the manipulating portion 42 severs from theanchoring flange head 50 at the weakened portion 39. This pin-severingoperation is repeated as required so that all of the channels 28accommodate pins 36 in partially protruding relation. It is clear thatthe weakened portion 39 is of sufficient reduced thickness to permit aready severing of the manipulating portion 42 from the flange head 50and threaded portion 38 without overstressing the tooth understructurelaterally or axially which may otherwise fracture the toothunderstructure.

Having a rod inserted in each channel, the ultimate step is to build thesuperstructure on the exposed excavated surface now provided withanchoring projections utilizing the potential support capacity of theunderstructure of the tooth for anchoring the superstructure thereto.This latter procedure, which does not form the basis of the presentinvention, has been described in my U.S. Pat. No. 3,434,209, issued onMar. 25, 1969, to which reference may be made, and results in a repairedtooth, as shown in FIG. 7, wherein the superstructure 26, having anupper surface 29, is fixed to the understructure or body [4 of thetooth.

It is noteworthy, that as the anchoring flange head 50 is embedded inthe superstructure 26, there is effected an enhanced resistance todisplacement of the superstructure 26 relative to the understructure 14.It is possible that the threaded portion 38 of the anchoring pins 36 mayserve to anchor the superstructure 26 to the understructure M in theabsence of the anchoring flange head 50, but it is equally clear thatprolonged prevention of displacement of the superstructure 26, relativeto the understructure 14, cannot be adequately maintained in the absenceof an anchoring flange head 50. Clearly, therefore, the provision of ananchoring pin 36 with the enlarged anchoring flange head 50 and theseverability of the manipulating portion 42 from the latter, pursuant tothe present invention, is a vast improvement over those conventionallyknown.

It should be further clarified that the manipulating portion 42 has anelongate extent which is at least equal to, but preferably greater than,the elongate extent of the threaded body portion 38. This is importantto provide means for manipulating the dental anchor in areas in themouth of the patient which are inaccessible or at the very leastdifficult to operate in. The enhanced elongate extent of themanipulating means 42 serves to accom lish this end.

It should be underst of course, that the foregoing disclosure relates toonly a preferred embodiment of the invention and that it is intended tocover all changes and modifications of the example of the inventionherein chosen for the purpose of the disclosure, which modifications donot constitute departures from the spirit and scope of the invention.

What is claimed is:

l. A dental anchor for securing a superstructure to a toothunderstructure, said dental anchor comprising an elongate member, saidelongate member integrally including a selfsecuring anchoring portionfor operative association with a tooth understructure, adisplacement-resisting anchoring portion for operativedisplacement-resisting association with a superstructure, a manipulatingportion for permitting manipulation of said self-securing anchoringportion, and a weakened portion interposed between said manipulatingportion and said displacement-resisting anchoring portion for permittingselective self-severing of the two latter said portions from oneanother, said manipulating portion terminating in a free end and havingan elongate extent substantially the same as the elongate extent of saidself-securing anchoring portion, said free and including means forpermitting self-severing of said manipulating portion from saiddisplacement-resisting anchoring portion.

2. A dental anchor as claimed in claim 1, wherein said weakened portionis constituted as a portion of reduced thickness in said elongatemember.

3. A dental anchor as claimed in claim l, wherein said selfsecuringanchoring portion is constituted as a helically threaded externalportion of generally cylindrical extent.

4. A dental anchor as claimed in claim 1, wherein saiddisplacement-resisting anchoring portion includes a pair of opposingflange faces generally extending laterally of said elongate member.

5. A dental anchor as claimed in claim 4, wherein said pair of opposingflange faces are of generally annular extent.

6. A dental anchor as claimed in claim 5, wherein said pair of opposingflange faces are of greater lateral extent than that of said elongatemember.

7. A dental anchor as claimed in claim 6, wherein said selfsecuringanchoring portion includes a helically threaded surface terminatingatone flange face.

8. A dental anchor as claimed in claim 2, wherein said elongate memberis metallic and of sufficient reduced thickness at said weakened portionsuch that said manipulating means is readily severable from saiddisplacement-resisting anchoring portion simply upon rotation of the twolatter said portions relative to one another.

9. A dental anchor as claimed in claim 8, wherein said manipulatingportion includes guide means for axially guiding the elongate memberinto operative association with the tooth understructure, andtorque-transferring means for rotatably displacing said self-securinganchoring portion into operative association with said toothunderstructure.

10. A dental anchor as claimed in claim 9, wherein said guide meansincludes a frusto-conical extent cooperable at least in part with adental tool and terminating in a portion of minimum diameter at saiddisplacement-resisting anchoring portion to constitute said weakenedportion, and said torque transferring means includes a pair of opposingendmost flat faces responsive to rotation of the dental tool.

11. A dental anchor as claimed in claim 8, wherein said manipulatingmeans has an elongate extent which is slightly greater than that of saidself-securing anchoring portion.

1. A dental anchor for securing a superstructure to a toothunderstructure, said dental anchor comprising an elongate member, saidelongate member integrally including a self-securing anchoring portionfor operative association with a tooth understructure, adisplacement-resisting anchoring portion for operativedisplacement-resisting association with a superstructure, a manipulatingportion for permitting manipulation of said self-securing anchoringportion, and a weakened portion interposed between said manipulatingportion and said displacement-resisting anchoring portion for permittingselective self-severing of the two latter said portions from oneanother, said manipulating portion terminating in a free end and havingan elongate extent substantially the same as the elongate extent of saidself-securing anchoring portion, said free and including means forpermitting self-severing of said manipulating portion from saiddisplacement-resisting anchoring portion.
 2. A dental anchor as claimedin claim 1, wherein said weakened portion is constituted as a portion ofreduced thickness in said elongate member.
 3. A dental anchor as claimedin claim 1, wherein said self-securing anchoring portion is constitutedas a helically threaded external portion of generally cylindricalextent.
 4. A dental anchor as claimed in claim 1, wherein saiddisplacement-resisting anchoring portion includes a pair of opposingflange faces generally extending laterally of said elongate member.
 5. Adental anchor as claimed in claim 4, wherein said pair of opposingflange faces are of generally annular extent.
 6. A dental anchor asclaimed in claim 5, wherein said pair of opposing flange faces are ofgreater lateral extent than that of said elongate member.
 7. A dentalanchor as claimed in claim 6, wherein said self-securing anchoringportion includes a helically threaded surface terminating at one flangeface.
 8. A dental anchor as claimed in claim 2, wherein said elongatemember is metallic and of sufficient reduced thickness at said weakenedportion such that said manipulating means is readily severable from saiddisplacement-resisting anchoring portion simply upon rotation of the twolatter said portions relative to one another.
 9. A dental anchor asclaimed in claim 8, wherein said manipulating portion includes guidemeans for axially guiding the elongate member into operative associationwith the tooth understructure, and torque-transferring means forrotatably displacing said self-securing anchoring portion into operativeassociation with said tooth understructure.
 10. A dental anchor asclaimed in claim 9, wherein said guide means includes a frusto-conicalextent cooperable at least in part with a dental tool and terminating ina portion of minimum diameter at said displacement-resisting anchoringportion to constitute said weakened portion, and saidtorque-transferring means includes a pair of opposing endmost flat facesresponsive to rotation of the dental tool.
 11. A dental anchor asclaimed in claim 8, wherein said manipulating means has an elongateextent which is slightly greater than that of said self-securinganchoring portion.